Field of the Invention
This invention relates generally to ore dressing methods and to concentration of metal values in ores by flotation. More particularly, the invention provides a new and valuable method of rcovering metal values from ores, whereby froth flotation of a slurry of the ore is conducted in the presence of a synergistic collector consisting essentially of a mixture of certain alkyl xanthogen alkyl formate compounds with certain dialkyl thionocarbamate compounds.
Flotation is a widely used method of concentrating ores, and believed to be the most commonly used ore dressing process. It is based on the principle that when air bubbles are introduced into a ground ore pulp, particles of desired minerals will adhere to the air bubbles, be released from the ore and float to the surface. Other undesired minerals or gangue will not adhere to the air bubbles and will remain in the ore pulp. Certain chemicals facilitate the flotation process by conferring a water-repellency or hydrophobic property to the surface of the minerals. Chemicals which impart this hydrophobic or water-repellent property are generally called "promoters" or "collectors." Herein, they will be referred to as collectors.
Industrially, collectors for use in flotation are of great importance because even a very small improvement in collector efficiency can have a significant commercial benefit. With the growing current practice of tailings retreatment, the efficiency of the collector employed becomes increasingly significant. Additional concerns are toxicity and environmental conditions as well as ease of storage and handling.